Fluorescent lamps are widely used for an on-board illumination device of a railroad car. In recent years, light emitting diode (LED) lights are being propagated as lighting devices instead of the fluorescent lamps. The on-board illumination device includes a plurality of lighting devices. At least several tens of lighting devices are provided in each car. In a case where accessory power supply devices are attached to those lighting devices, there are problems on a mounting space, weight, and the like.
However, a technology in which an integrated power supply device is used for supplying power to the plurality of illumination devices and power is supplied from that power supply device to each illumination device is known. For example, Patent Literature 1 has disclosed a railroad car configured such that a common power supply device supplies power to a plurality of LED illumination devices connected in series.